KR19980056789A - Syndiotactic polystyrene-based thermoplastic resin composition - Google Patents

Abstract

The present invention provides a syndiotactic polystyrene-based thermoplastic resin composition composed of the following composition, the syndiotactic polystyrene-based thermoplastic resin composition of the present invention is excellent in the balance of physical properties such as impact strength, elongation and heat deformation temperature Not only workability also has excellent advantages:

(A) Syndiotactic Polymerization with Heteroatom Bridge Two Metal Metallocene Catalysts

1 to 90 parts by weight of polystyrene,

(B) A vinyl aromatic graft rubber copolymer obtained by graft polymerization of 20 to 99 parts by weight of an aromatic vinyl monomer to 1 to 80 parts by weight of a rubbery polymer.

1 to 50 parts by weight, and

(C) 0-40 weight part of alkenyl aromatic hydrocarbon resins.

Description

Syndiotactic polystyrene thermoplastic resin composition

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a synmotactic polystyrene-based resin composition, and more particularly, to synthactic polystyrene polymerized with a metallocene metal catalyst and polystyrene made of general radical polymerization. It relates to a syndiotactic polystyrene-based thermoplastic resin composition excellent in impact properties.

Stereoregular polystyrene, which has not been available until recently, is now manufactured using metallocene catalysts. The metallocene catalyst is composed of a metal compound consisting of transition metals (e.g., titanium, zirconium, hartium) of the Group IVb of the periodic table and one or two cyclodienyl groups (e.g., cyclopentadienyl, indenyl, fluorenyl) The resulting ligands have a bonded structure in the form of a sandwich. Cocatalysts used are, unlike Ziegler-Natta catalysts, alkyl aluminum oxanes (eg, methylaluminum oxane), which are reactants of water with alkyl aluminum compounds.

This syndiotactic polystyrene is a structure in which the benzene rings in the polymer main chain are alternately positioned. Unlike conventional amorphous general atactic polystyrene, the syndiotactic polystyrene has a crystalline structure and has a melting point (Tm) of 270 ° C. It is attracting attention because of its excellent mechanical and electrical properties.

However, syndiotactic polystyrene has a disadvantage in that the decomposition temperature of the resin is difficult to be processed near 300 ° C. and the impact resistance is weak. In order to overcome these drawbacks and provide good processability, researches to lower the melting point in the polymerization process are actively conducted. In particular, Japanese Patent Laid-Open No. 5-186658 proposes a method of copolymerizing with a monomer having an unsaturated group (for example, ethylene, butadiene, etc.). Japanese Patent Laid-Open No. 4-085311 proposes a method of copolymerizing with a monomer having a side chain. In addition, Japanese Patent Laid-Open No. 1-131263 discloses a method in which a small amount of polypropylene is added to copolymerize with a styrene monomer.

On the other hand, as a method of improving the impact resistance of the syndiotactic polystyrene-based thermoplastic resin composition, Japanese Patent Application Laid-Open No. Hei 4-40014 has a method of preparing a graft polymerized polybutadiene rubbery polymer and then putting it in a toluene solvent and polymerizing the same. Presented.

In the composition part, European Patent 0318793 proposes a technique of increasing the impact strength by using a high impact polystyrene, styrene-butadiene-styrene triple copolymer. However, the methods and compositions described above have a limitation in that sufficient impact strength improvement cannot be achieved.

Japanese Patent Laid-Open No. 4-279646 discloses a method of adding a core-shell type copolymer during blending to improve impact resistance. In this method, core was used an acrylate rubber or diene rubber, and the shell resin was prepared using a vinyl compound, an acrylate resin. However, such a core-shell copolymer has a problem in that it cannot have high impact strength because it is not sufficiently compatible with syndiotactic polystyrene.

SUMMARY OF THE INVENTION An object of the present invention is to overcome the problems of the prior art as described above, to prepare syndiotactic polystyrene having good processability using a heteroatom bridged binuclear metallocene catalyst (HBBT) and to vinyl aromatic graph It is to provide a syndiotactic polystyrene-based thermoplastic resin composition having excellent workability and impact resistance by preparing and blending a rubbery copolymer and an alkenyl aromatic hydrocarbon separately.

That is, the present invention is to provide a syndiotactic polystyrene-based thermoplastic resin composition composed of the following composition:

(A) Syndiotactic Polymerization with Heteroatomic Bridge Bimetallic Metallocene Catalysts

1 to 90 parts by weight of polystyrene,

(B) A vinyl aromatic graft rubber copolymer obtained by graft polymerization of 20 to 99 parts by weight of an aromatic vinyl monomer to 1 to 80 parts by weight of a rubbery polymer.

(C) alkenyl aromatic hydrocarbon resin

1 to 50 parts by weight, and 0 to 40 parts by weight.

Hereinafter, the present invention will be described in more detail.

Preparation of the catalyst

Heteroatom bridging bimetallic catalyst used in the present invention is a π-electron cyclopentadienyl, alkyl-substituted cyclopentadienyl η ⁵ bond in which a metal of Groups III to IV, a transition metal of Group IVb, or a lanthanum atom is bonded Indenyl or fluorenyl or a derivative compound thereof to form a compound having a structural formula (I) or (II) connected by a bridge containing a hetero atom.

In the above formula,

M is a metal of group III-IV of the periodic table, transition metal of group IVb or lanthanum atom,

Yl and Y2 are independently of each other π-electron cyclopentadienyl, alkyl-substituted cyclopentadienyl, indenyl, fluorenyl, or derivatives thereof capable of bonding M and η ⁵ ,

A1, A2 and A3 are independently of each other transition metals or lanthanide atoms of group IVb of the periodic table,

Sp is a spacer, carbon, oxygen, nitrogen or phosphorus,

E1 and E2 are heteroatoms nitrogen, oxygen, phosphorus or sulfur,

R 1 to R 6 are independently of each other hydrogen, alkyl, aryl, silyl, alkoxy, aryloxy, siloxy, halogen, a group formed from a combination thereof, or -Sp-Sup (Sup is a support)

X is a group formed of hydrogen, alkyl, aryl, silyl, alkoxy, aryloxy, siloxy, halogen, a combination thereof,

n is an integer of 0 to 4,

Z is a non-coordinating anion that is not coordinating or weakly coordinating to the Y-containing metal cation moiety so as not to prevent other Lewis bases from interacting with the Y-containing metal part of the cation. , Preferably _1-10 ^{5- 5} _{4 2 2 4 2 2} ⁵ ₃

The structure of the catalyst shown in Table 1 was investigated by hydrogen and carbon nuclear magnetic resonance analyzers (H-NMR and C-NMR), and the side component and composition were analyzed by an inductive plasma spectrometer (ICP).

The stereoregularity of Table 1 shows the catalytic activity as Kg Ps / g Ti-St mol-h by measuring the weight of styrene obtained in the polymerization.

In order to measure the syndiotactic index (S.I) of the obtained polystyrene, the stereoregularity of Table 1 was extracted with methyl ethyl ketone, and the weight of the polymer remaining after extraction was obtained to express S.I as a percentage.

Melting point and crystallization temperature of Table 1 was measured by differential thermal analyzer (DSC), the sample was heated to 200 ℃ and left for 5 minutes and then measured while cooling the temperature rise and temperature rate was 20 ℃ / min.

Through Table 1, it can be seen that the polymerization activity is higher and the stereoregularity is higher than the case of using Cp * TiCl when polymerizing styrene using the HBBT compound of the present invention. The melting and crystallization temperatures of polystyrene polymerized using HBBT were similar to those of polymers obtained using Cp * TiCl. The molecular weight of syndiotactic polyester was changed to 10 by changing the catalyst component ratio or polymerization temperature. 10 In particular, it was adjustable over 5,000-200, 000. The molecular weight distribution (Polydispersity index) at this time was able to adjust the 1.5-7.0 degree. In the case of using the HBBT compound of the present invention as a catalyst, syndiotactic polystyrene having better catalytic activity, stereoregularity, and crystallization temperature can be prepared when using a catalyst which can be generally used.

Example 2

(1) vinyl aromatic graft copolymer

300 g of polybutadiene latex (based on solids) and 700 g of styrene having a rubber particle diameter of 0.1 µm are placed in a reactor, and 5 g of potassium persulfate and 5 g of sodium moleate are added to the mixture to emulsify and polymerize the vinyl aromatic graft copolymer (B) was obtained.

(2) Preparation of syndiotactic polystyrene thermoplastic resin composition

80 parts by weight of the syndiotactic polystyrene resin obtained by Example 1, 10 parts by weight of the vinyl aromatic rubber copolymer obtained in the step (1), 10 parts by weight of high impact polystyrene, antioxidant (PHT) and thermal stabilizer ( PEP36) 0.2 parts by weight were mixed and melted in a coaxial twin screw extruder (Berstroff, Germany) having a diameter of 40 mm and pelletized.

At this time, the processing conditions were set to the extruder cylinder temperature 250 ~ 290 ℃ screw speed 300rpm. Subsequently, the obtained pellets were dried at 80 ° C. for 1 hour, and then injected into an ASTM family mold under a molding temperature of 290 to 320 ° C. and a mold temperature of 80 to 140 ° C. in a 60 oz injection machine to prepare a physical specimen.

The results of the cladding properties of the specimens thus obtained are shown in Table 3 below.

Comparative Examples 2-7

As shown in Table 2 below, except for changing the end and the content of each component pelletized syndiotactic polystyrene-based thermoplastic resin composition in the same manner as in Example 2, and evaluated the overall physical properties and the results are shown in Table 3 Shown together.

Through the above Table 3, the syndiotactic polystyrene-based thermoplastic resin composition of the present invention prepared by using a vinyl aromatic rubber polymer as an impact modifier in a syndiotactic polystyrene polymerized using an HBBT catalyst is a high-impact polystyrene or a general polystyrene resin. It can be confirmed that the physical properties of high impact strength, elongation and heat deflection temperature are excellent compared to those of the present invention.

Simple modifications or changes of the present invention can be easily carried out by those skilled in the art, and all such modifications or changes can be seen to be included within the scope of the present invention.

Claims (10)

(A) Syndiotactic Polymerization with Heteroatomic Bridge Bimetallic Metallocene Catalysts 1 to 90 parts by weight of polystyrene, (B) 1 to 50 parts by weight of a vinyl aromatic graft rubber copolymer obtained by graft polymerization of 20 to 99 parts by weight of an aromatic vinyl monomer to 1 to 80 parts by weight of a rubbery polymer, and (C) A syndiotactic polystyrene-based thermoplastic resin composition comprising 0 to 40 parts by weight of an alkenyl aromatic hydrocarbon resin. The syndiotactic polystyrene-based thermoplastic resin composition according to claim 1, wherein the heteroatom bridging metallocene catalyst has a structure of the following general formula (I). Wherein M is a metal of Groups III to IV of the periodic table, a transition metal or a lanthanum atom of Group IVb, Y1 and Y2 are independently of each other a π-electron cyclopentadienyl, alkyl substituted with M and η ⁵ -substituted Cyclopentadienyl, indenyl, fluorenyl, or derivatives thereof, and A1. A2 and A3 are independently of each other transition metals or lanthanum atoms of group IVb of the periodic table, Sp is carbon, oxygen, nitrogen or phosphorus as spacer, E1 and E2 are nitrogen as hetero atoms. Oxygen. Phosphorus or sulfur, R 1 to R 6 are independently of each other hydrogen, alkyl, aryl, silyl, alkoxy, aryloxy, siloxy, halogen, a group formed from a combination thereof, or -Sp-Sup (Sup is a support), X Is a group formed of hydrogen, alkyl, aryl, silyl, alkoxy, aryloxy, siloxy, halogen, or a combination thereof, and n is an integer of 0-4. The syndiotactic polystyrene-based thermoplastic resin composition according to claim 1, wherein the heteroatom bridging metallocene catalyst has a structure of the following general formula (II). In the above formula, M is a metal of group III-IV of the periodic table, transition metal of group IVB or lanthanum atom, Y1 and Y2 are independently of each other π-electron cyclopentadienyl, alkyl-substituted cyclopentadienyl, indenyl, fluorenyl, or derivatives thereof capable of bonding M and η ⁵ , and A 1, A 2 and A 3 are Independently of one another is a transition metal or lanthanum atom of group IVB of the periodic table, and Sp is carbon as a spacer. Oxygen, nitrogen or phosphorus, E1 and E2 are heteroatoms nitrogen, oxygen, phosphorus or sulfur, and R1 to R6 are independently of each other hydrogen, alkyl, aryl, silyl, alkoxy, aryloxy, siloxy, halogen, combinations thereof Or-Sp-Sup (Sup is a support), X is a group formed of hydrogen, alkyl, aryl, silyl, alkoxy, aryloxy, siloxy, halogen, a combination thereof, and n is 0-4 Integer, z is Where s is boron, Are independently selected from the group consisting of hydrogen anhydride, dialkylamido, alkyloxide, hydrogen carbyl and organometalloid. One of them is a halide. The cyclopentadiene according to claim 1, wherein the heter atom bridge bimetallic metallocene catalyst reacts with a cyclopentadienide, indenylide, or fluorenide containing an alkali metal cation to a heter atom bridge compound. Syndiotactic polystyrene-based thermoplastic resin prepared by preparing a heteroatom bridge compound having two groups, such as a nil group, an indenyl group, or a fluorenyl group, and reacting the hetero bridge compound in the salt state with a transition metal compound of group IVb of the periodic table. Composition. The transition metal compound according to claim 4, wherein the transition metal compound of Group IVb of the periodic table is combined with a group selected from the group consisting of hydrogen, alkoxy, aryl, alkoxy, aryloxy, siloxy / halogen and combinations thereof Syndiotactic polystyrene-based thermoplastic resin composition, characterized in that the compound. The syndiotactic polystyrene-based thermoplastic resin composition according to claim 5, wherein the transition metal compound of Group IVb of the periodic table is titanium tetrachloride (TiCl ₄ ). The rubbery polymer of the vinyl aromatic graft rubber copolymer is at least one selected from the group consisting of a rubber of a terpolymer of a diene rubber, an acrylic rubber and an ethyl-propylene-diene monomer. Syndiotactic polystyrene-based thermoplastic resin composition. 8. The syndiotactic polystyrene-based thermoplastic resin composition according to claim 7, wherein the rubber particles of the rubbery polymer have an average particle diameter of 0.02-1 mu m. The method of claim 7, wherein the aromatic vinyl monomer of the vinyl aromatic graft solid copolymer is styrene, t-butyl styrene, alphameryl styrene, p- methyl styrene, vinyl toluene, monochlorostyrene, dichlorostyrene, dibromo Syndiotactic polystyrene-based thermoplastic resin composition, characterized in that at least one selected from the group consisting of styrene, ethyl styrene, vinyl naphthalene, divinylbenzene The method of claim 1, wherein the alkenyl aromatic hydrocarbon is at least one member selected from the group consisting of polystyrene, high impact polystyrene (HIPS), polychlorostyrene, poly alpha-methylstyrene, poly t-butylstyrene, and copolymers thereof. Syndiotactic polystyrene-based thermoplastic resin composition, characterized in that.